Cylinder head



2 Sheets-Sheet 1 BY HRTHUR BooR TT NEY A.BOOR

CYLINDER HEAD Filed OC. 22. 1925 Feb. 25, 1930.

Feb. 25, 1930. A. BOOR 1,748,105

CYLINDER HEAD Filed 00t- 22, 1925 2 Sheets-Sheet 2 I N VEN TOR.

15 to provide for the increased j patented Feb. 25, 193e .ARTHUR BOOR, OF TOLEDO, OHIO,

ASS-IGNOR TO THE WIIIiLYS-OV'ERLAND COMPANY,

OF TOLEDO, OHIO, A CORPORATION F OHIO CYLINDER HEAD Application inea october 22,'1925. serial no. 64,064.

,This invention relates to internal combustion engines and more particularly to engines of the poppet valve type in which the cylinder head is removable.- One of the objects of the invention is to provide an engine with a removable 'cylinder ead that is composed of a material having high heat conductivity characteristics.

Another object ofthe invention is to provide a multi-cylinder engine with individual 'cylinder heads. Y A further object of the invention is to provide a multi-cylinder engine with cylinder headsof a highlyfconductive material and expansion due to the use of such a material.

Other objects relatingy to details of construction and economies of manufacture, will appear from the-description of the invention to follow, certain embodiments of which, forA the purposes of the present application, I have illustrated in the accompanying drawin s, in which e igure I is a transverse vertical cross section of an engine embodying one form of the invention. l

Fig. II is a top plan of the cylinder block with the head removed, the view being taken substantially on the line 2-2, Fig. I. Fig. III is a'plan-view of the engine cylinder portion-showing'the cover in position.

Fig. IV is a sectional view of the cover and cylinder head taken on line 4-4 of FigcIII. Fig. V is a plan view of the cylinderhead used on the cylinder to the extreme left as shown in Fig. II.

Referring to the drawings in which-iik@- numerals refer to like parts throughout the 4 several views, 1 represents a cylinder of an cates piston 2 connected to-crankshaft 3 by rod 4. Covering the upper end of cylinder 1 and valves 9 is a head 5 of a material having highheat'conducting characteristics. such as aluminum. .Head 5 is secured to the main cylinder casting 6 by studs 7 and nuts 8 and is somewhat-dome-shaped over valves 9 in order to allow the valves to clear the head .when raised' to their open position and also to 5 'provide a clear passage to the cylinder 1.

internal combustion engine in which recipro-v A separate head 5 is provided for each'of the en gme cylinders, all heads being substantially alike except for .the manner in which they are secured to the cylinder casting. Thev heads covering the end cylinders are provided at one side with holes 10 through which, project the studs 7 and at the other side with semi` circularnotches 11 which align with similar notches on the mating side of the adjacent head and permit the contiguous sides of adjacent heads to be held with the same studs. The heads for the vintermediate cylinders, of a four cylinder engine such as illustrated will have semicircular notches on both sides of head 5 because each side of the head is adjacent a similar side of another head. Openings 12 are provided in head 5 which communicate with the cylinder surrounding space 13, by means of opening 14.

. A suitable cover 15 is adapted to cover all of the cylinders and is secured thereto by upward extensions of studs 7 and nuts 16, packing 17 being interposed between the head 5 and cylinder casting 6 to insure a tight joint. Each head 5 is provided with an upstanding portion 18- which projects through an opening 19 in cover 15 and permits the insertion of ignition plug 20.- Cover 15 is provided with a-conical depression immediately surrounding head portion 18 for the reception of packing ring 21 vwhich is forced into contact with the head portion 18 and cover 15, by washer 22 and nut 23. Cover 15, except at opening 19, is spaced from cylinder 5 so asto provide a n space 24', fora suitable cooling medium, which is in communication with the cylinder jacket space 1.3. Outlet 25 serve s to direct the cooling medium circulating 1n space 24 into a radiator (not shown) from whence itis returned to the engine jacket space 13, in the usual manner.

Internal combustion engines, as usually constructed, are surrounded by similar spaces containing a cooling medium but as the head portion is subjected to the greater heat it is desirable to construct the cylinder head 'of a material having high thermal conductivity and to construct the cylinder portion of a material, such as iron, having good wearing qualities and acting as an excellent bearing inder heads formed of a highly conductive material enable the engine builder to obtain more power froma given size engine, as the compression may be materially increased. At present, the compression is limited by fuel detonation which occurs in a hot engine after the compression exceeds a critical point which is usually around 65 to 70 pounds kper square inch, but if the heat of the head be dissipated at a higher rate, the compression may be raised beyond the previous critical point and the eiliciency of the engine increased. Unfortunately the use of a metal having high thermal conductivity introduces diliculties because of its relatively lhigher coefficient of expansion under heat. The difference in expansion during heating and cooling of a large engine produces considerable relative movement between the contacting surfaces and results in destroying the desirable leak-proof l contact between the head and cylinder. This is especially true of multi-cylinder engines in which the relative movement is increased proportionatelyto the length of the head that is necessary to cover all of the cylinders.

The present invention eliminates the above mentioned troubles by securing each cylinder head to its cylinder as a separate unit and then covering all of the heads with a single cover'in order to provide a cooling chamber common to all cylinders with a single outlet. The individual cylinders of vmulti-cylinder engines are of small dimensions as compared with the engine as a whole,-and the movement of each head relative to the cylinder is correspondingly reduced. Holes and grooves l0 and l1 may be made slightly larger than studs 7 but it has been found that the ordinary clearance given to holes of this character is quite suflicient and that if the holes are large enough to permit the free installation of head 5 onto cylinder casting 6 by sliding the head over studs 7, no trouble will be experienced.

' The use of individual heads reduces the' movev mentof each unit to an amount that does not destroy the joint between cylinder andl cylinder head and the mating surfaces may be kept tight indefinitely, while the encompassing cover permits of simple connections for the circulation of the cooling medium about the separate heads. I prefer Uto construct' the heads as individual units, so as to receive the maximumbeneiit from the use of the invention, butin small englnes or 1n those englnes wherein it is not considered necessary to obtain all possible -value of the invention, two or more heads may be cast together, even thoughv such procedure` lessens the derived benefit. v

While I have shown and. described, somewhat in detail, one embodiment of the invention, it is to be understood that this showing and description are illustrative only and'that I do not regard the invention as limited to the details of construction illustrated and de- `cylinder and a passage from its individual valves to said cylinder, said head having all of its cylinder contacting surface in the same plane, and a cover extending over al plurality of said heads and spaced therefrom there being a clearance horizontally between said heads and said cover, said cover being supported by said cylinders and means for securing said cover to said cylinders.

2. In a multi-cylinder poppet valve engine having inlet and exhaust valves arranged laterally of the cylinders, the combination of a separate cylinder head` for each cylinder, said head forming a closure for the upper end of said cylinder and a passageway from its individual valves to the cylinder, said head and cylinder having their contacting surfaces in the same plane, a cover secured to said cylinders extending over a plurality of cylinder heads and spaced therefrom for confining a cooling medium, jackets surrounding said cylinders and spaced therefrom, and` means permitting intercommunication lbetween the head space and the cylinder space whereby the cooling medium is free to circulate around said cylinders and said heads.

3. In a multi-cylinder engine having inlet and exhaust valves arranged laterally of the cylinders, the combination of cylinders having surrounding cooling spaces, separate closures for the upper ends of said cylinders, said closures being formed of a material having greater heat conductivity than the cylinder material and forming a passageway from its individual valves to said cylinders, and a cover spaced from but enclosing a plurality of said heads and forming with the walls of said cylinders a compartment in communication with the cylinder cooling spaces.

the cylinders, the combination of Separate heads for the engine cylinders, each of said v heads forming a passageway from its individual valves to its cylinder and formed of a material havinggreater heat conductivity lthan the cylinder material, a cover secured l to said cylinders `and inclosing a plurality of cylinder heads for directing a cooling mediumy about said heads, said cover having ing openings therein for allowing a portion of each of said heads to project therethroughA and `means for sealing'said opening.

5. In a multi-cylinder engine having inlet and exahust valves arranged laterally of the cylinders,

ing surrounding jacket spaces with openings the combination of cylinders havat the upper ends, a separate head secured to each of the cylinders composed of a material having a diii'erent heat conductivity from the material of the cylinders, said heads covering the upper end of the cylinders and extending over the valves for providing a passageway to said cylinders, a cover secured to said cylinders and extending over a plurality of said heads for forming a cooling mediumv enclosure, and means on said heads whereby the openings in the cylinder jacket spaces may communicate with the en- 'closurebetween said cover and said heads.

In a multi-cylinder engine having inlet and exhaust valves arranged laterally of the cylinders, spaced individual cylinder heads forming closures forthe upper ends of each of the cylinders, said heads providing in# dividual passageways from said valves to said cylinders, said heads being formedof a material having a higher thermal conductivity and a higher coelicient ofv expansion than the cylinder materialiand said heads being constructed as units formingclosures for a less number of' cylinders than the total number of cylinders included by the engine, and said heads being secured to saidA cylinders by means which permit slight relative motion. 7. In amulti-cylinder engine having inlet and exhaust valves arranged laterallyl ofthe cylinders, the combination of cylinderv heads composed of a material having a higher I v thermal conductivity and a higher coiicient of expansion than the cylinder material, said heads forming closures-for the upper ends of the cylinders and individual p'assageways from the valves to the cylinders, said heads being constructed as units formingclosures -fora less number of cylinders than the total number of cylinders 4included by the en ine and a single cover secured to the cylin ers and spaced from said heads for forming al compartment therewith. v

- In testimony whereof, I aix my signa- ARTHUR BOOR.

A ture. 

